comment on

Looking at the Camel book, 3rd edn., table 5-1 on page 150, the entry for /s says "Let . match newline ... " which sort of implies that /m doesn't. So it is the treatment of the "." metacharacter that changes between the two. This with no modifying flag also matches

($span_d) = $str =~ /(\d\d\w+\s\w+\d\d/;
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This might imply that the default behaviour of m/.../ with no modifying flag is the same as m/.../m. I will delve into the documentation when I get a chance.

Cheers,

Johngg

Update:

This passage is in the "perlre" manual page

...
     m   Treat string as multiple lines.  That is, change "^" and
         "$" from matching the start or end of the string to
         matching the start or end of any line anywhere within
         the string.

     s   Treat string as single line.  That is, change "." to
         match any character whatsoever, even a newline, which
         normally it would not match.

         The "/s" and "/m" modifiers both override the $*
         setting.  That is, no matter what $* contains, "/s"
         without "/m" will force "^" to match only at the
         beginning of the string and "$" to match only at the end
         (or just before a newline at the end) of the string.
         Together, as /ms, they let the "." match any character
         whatsoever, while still allowing "^" and "$" to match,
         respectively, just after and just before newlines within
         the string.

...

perl v5.8.4          Last change: 2004-01-17                    1
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In reply to Re^4: Passing variables into regular expressions by johngg
in thread Passing variables into regular expressions by wanderer

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